Carburetor



Feb. 6, 1923. 1444,4226.

W. P. PEMBROKE.

CARBURETOR. v FILED MAR. 2,'I.915. 2 SHEETS-SHEET 1- WITNESSE: a v D mil Emma Patented eh. 6,

CARBURETOR.

Application filed March 2, 1915.

To all whom, it mrcz concern:

Be it known that l, Wnirinrin P. PEM- BROKE, of Rochesterfln the county of Monroe and State of New York, have invented certain new and useful Improvements in Carburetors; and I do hereby declare the following to be a full, clear, and exact descriptions of th same, reterence being had to the accompanying drawings, formin a part of this specification, and to the reference numerals marked thereon.

My present invention has for its object to provide a carburetor for vaporizing liquid fuel for use in explosive engines in which two different sources of supply of fuel are provided, one for furnishing the rich mixture required for low speed operations of the engine, or when the engine is being first started, and the other for furnishing the leaner carbureted mixture used for higher speeds, the parts of the carburetor being so arranged that the operation of these two instrumentalities is automatic and is governed by the demands created by the engine, under varying conditions of the load applied to the engine. To these and other ends the invention consists in certain improvements and combinations of parts all as. will be herein after more fully described, the novel features bein pointed out in the claims at the end of the l ilication.

in the drawings:

F igure l is a side elevation of a carburetor showing one embodiment of my present invention;

Figure 2 is a top plan view thereof;

Figure 3 is a vertical central sectional view, and

Figure 4 is a detail sectional view taken on the line lof i igure 1.,

Similar reference numerals throughout the several views indicate the-same parts:

My present invention provides a carburetor having a dual source of fuel supply whereby the greatest efliciency can be developed in an explosive engine, one of the sources intended particularly to supply the required amount of liquid fuel to produce the rich mixture required when the engine is working at low speed, as occurs when the cranking operation is performed to start it, or when the engine is endeavoring to develop its maximum power at a low number of revolutions, while the second source of fuel supply, which operates conjointly with the one first mentined f rnishes the fuel which is greater rapidity.

Serial No. 11,571.

to be mixed with the greater volume of air drawn throu h the carburetor when the pistons of the engine are reciprocated with With this last mentioned means of supplying the liquid fuel automatic valves are employed which are operated by the inrushing air to control the admittance of air in the required quantities to form a proper carbureted mixture.

In carrying out my invention a cal'bureting chamber having a receptacle for liquid fuel, such as gasoline, the quantity of which admitted to the receptacle is pro- 1 provide portioned to the requirements of the particular engine with which the carburetor is to be used. i l/leans are also provided in the chamber whereby the volume of the air currents traversing the chamber is caused to pass into intimate contact with the surface of the fuel held in the receptacle, or if needs be, to p, through the body of fluid to the end that the air may become saturated and a v rich explosive mixture created. he arrzmu'ement of the fluid inlet by which the liquid fuel is supplied to the receptacle is so arr g'ed that after the latter has been emptied and the very rich carbureted mixture provided at the outset for the starting of the engine, is exhausted the receptacle will not he again filled while the engine is in operation, the fluid which passes into the chamber being evaporated and utilized at low engine speed operation before it gravitates into the receptacle.

In illustrating one embodiment of my present invention I have shown a carburetor compr sing a hollow casing forming a mixing chamber A and a float chamber B, which are arranged side by side, the former hariu the primary air inlet 1 and the outlet i2 controlled by the usual throttle 3 which is opened and closed by the lever l, The air inlet 1 is arranged somewhat above the lower end or bottom of the chamber A and within lower end of the chamber A and may be provieed with a shallow depression or recess 6 Extending through the part 6 is a tubular screw 7 which is adjustable from the exterior of the carburetor and constitutes an or w or stand pipe for controllin the level which the bot oi liquid fuel in the bottom oil the chaniliier A. may assume. .iilso :jirranged in the chamber A andv cooperating with the receptacle is an adjust-able air valve H, which is semi-(n bndrical in cross section and forms a movable lower end on the partition 5 which can be adjusted to determine the thickness oi? the air sheet passing beneath the partititm, the proximity which the volume or main portion of air currents assume to the surface of the liquid contained in the bottom of the mixing chamber, or to cause said air to pass through the body of the liquid fuel until, this is'completely evaporated; The adjustment of the valve or gate 8 depends prin ipally upon the gravity of the fuel and the condition of the r at different times. @ther forms of: valves may be used in lieu of the vaive or gate 8, or other expedients adopted to control the thickness oi the air sheet for instance the plug 6 may be rotated and thus raised or lowered relatively to the lower end of the partition 5. The air valve 8 cooperating with the fluid receptacle extends tramsversel; ofthe mixing chamber and is jourmilcd in the side walls thereof and exteriorly of the chamber at one of its ends it is provided with a head t having a transverse arm or handle l9,

The :luel is admitted into the mixing chamber from the float chamber 1 through the nozzle or orifice 9, the area thereof being controlled by a needle valve 10 which is adjusted by a thumb nut ll on the 'thrcz'ided outer extremity of the valve stem The latter is guided to move lon uinally in apertures in the wall of the caste the partition 5 and the exteriorly arranged bracket 13 and it is held yieldiugzly in its innermost adjusted position by means olf a coil wring:

14 so that the needle valve may be r ed to allow the erifice 9 to be opened to perurut the unrestricted flow of the liquid 'lrom the chamber B into the chamber A. This adjustment of the needle valve may be accomplished. in any suitable manner the means shown ccnsi 'ug' of a cam l5 iourualed on. a pivot 16 car ed on the sleeve 1'?" and idly connected to the val e stem 12 the cam moved by apull rod 13 or other le device, and bearing against the v t n1 loud wall. of the casing will move one s tudinally in an outward direction.

At the side of the chamber A is a tubular extensionyv normally closed at its inner end by a re. o head 24- aud having at each side apertures 25, the area of: which may be adjusted by a collar 26 which is locked in the adjustodposition by a screw 27.- These parts constitute an auxiliary air inlet through -which the required volume of air may be admitted to furnish the carbureted mixture requiredfor intermediate engine speeds At niands of the engine increase the suction of air in the chamber A increases the quantity ot fuel suppliechup to a given point, which sutlicient to ci'bturet the additional supply of air which may be admitted through the auxiliary air inlet and when the limit of the capacity of this is reached further carburation issupplied for the maximum capacity of the engine by bringing into play an additional :tuel nozzle and air inlet.

The fuel supplied for the higher speed operations of an. engine is obtained through a jet or nozzle 28, the lower open end 29 of which is located in the float chamber, B below the orifice 9, while its upper end leads int-o the auxiliary air inlet A, the latter being preferably located over the float chamber to permit this simple arrangement oi? the parts. The flow of the fluid through the nozzle may be controlled by the needle valve formed at the inner end of the screw threaded adjustable stem 28 projecting upwardly through the bottom of the float chamber in alinement with the seat 28 lhe outer end of the auxiliary air inlet A is normally closed by an apertured face plate a. against which rests a secondary valve head 29. Both valve heads 24 and 29 are slidably supported on a rod 30 and are (-0 that the valve 24; will be drawn inwardly to admit the amount of air required to supply the increased demands of the en- ;rinc up to the full ca pa bilities of the nozzle to effect carhura iod Further increasing demands of the e me upon the carburetor are met by the opening; of the fe in /29 which uncovers the aperture in the face plat a a d the adjustment of the parts is such that at this instant the suction created causes the aspiration ct fuel from the nozzle 2%. The opening movement oi. the valves 2% and 29 may be regulated to a nieety by adjusting the tension of the spring 50 and the 111M118 which I have shown for accom end of the spring engages. Independent adjustment oi the spring 31 is not required as it'is customary to use alight spring, the tension of which is reduced when the valve head 24; is retracted, the reduction of the tension depending also upon the distance the nilve head 2-1: is moved inwardly;

The arrangement oi. the parts as shown is more than the combining of trm carburetors because in addition to bringing these parts together I have so arranged them with the two air valves and the air inlet that l have provided in the secondary carburetor means whereby it is possible to govern to a nicety the time, or instant, according to the demands of an engine. at which the supply of auxiliary air for the primary iuel nozzle and the quantity of such air shall be ad mitted; and further, a point which is of greater importance, 1 am able to govern the exact instant, during the period. of speed increase of the engine, at which the dis charge of fuel from the secondary nozzle shall begin. In other words, the arrangement of the two valve heads in the lateral passage A. with'an air inlet 25, of adjustable area, enables the fuel supply from the nozzle 28 to be checked while the necessar volume of air to satisfy the increased flow of fuel from the primary nozzle 9 is allowed to pass through the opening cont-rolled. by the-valve 24. It is understood of course... that there is quite a range of spe ds at which an engine can be operated on the n'iixture supplied by the nozzle 9. the main airinlet 1 and the auxiliary air inlet comprising the apertures 25 and the opening controlled by the valve 24, but when the maximum speed is reached that can he maintained by this source of supply it is highly important that the secondary fuel nozzle should begin to supply fuel and that still further quantities of air be then allowed to flow into the mixing chamber in exact proportion to the additional fuel supply.

The arrangement of the mechanism of the float chamber. by which the level of the liquid therein is'controlled. maybe of: any desired construction and for the purpose of illustration I have shown the float b can ried on the valve stem Z which opens and closes the inlet passage 32, In order to trip the float to perform the priming operation so that the level of the liquid fuel may rise to such a height that it will flow through the orifice 9 I provide in the top of the float chamber a spring retracted pin 33 which may be depressed by a bell crank lever 34, tripped by a cord or cable leading preferably to a central point oi control from which the similar cord 18 ated.

It will be noted that the springs and 31 are of such relative strength that the spring 30 will permit the operation of the is operval ve 1116 w. lve the air iudepcndcntly o? the operation ol? '3 however, the reduction oi 1n the auxiliary mixing chamber i is sufiicient when the valve 24-. 15 open t e valve 559" will also be actuated.

l 'hc rr-c ion of the Valve reduces the our-ion oi? the spriug 3] on the vahe E29 permitting the ()llilliLtEOD oil the latter val re only when the valve 9-1 is open.

it Will also be noted "that the nozzle 9 is some distance of the floa 7 v v a: i chamber am. i leading L0 th nozzle 28 i bottom oi sau air being: sl

lin order to prere c said noztzles a. pa I tion T1 is prom led in tie float chamber e1;- tend' i from a point near the hoitom there of to the and enclosing;- the fuel assage-a 9 and 29 The partition extends below the normal surface ot the fuel in the chamber E and hence prevents adm ssion of air in the chamber to the fuel iand 29.

The nozzle 9 is above the d by such d through l l: hereiore. the to supply engine is u the is. 01 course. vaporin-c-d and Liquid l'url r-iav thus be reason to flow through the nozzle tenuioru" during the priinii operation w through the nozzle continuously operation but at all 0* times the is below nozzle 9 so that no fuel is the coming air supplied to the ea ns),

taken 11 p )V liqu wasted.

low Q losed. M-

lre ill remairs however. valve f the tie-flut d name speeds in uu'rcaseu spccdu V rclv. is l .,..-.l'=ictio:o o pressure in the su e her A is not sutliciuit to draw through uoz-ztle so that in operation. Air inlets adjusted to such a constant ope; tine ct cpenin that the pressure in the secruularv chamber A falls at that hioher speed of the engine or in other words at that redi'iced pressure in primary chamber r which it is desired to bring the nozzle 8 into operation. In other words the openin "s 25 are so adjusted as to be insutlicient in size to supply are manually the increased volume. of air drawn past the open valve 24- by the reduced pressure in primary chamber A, and at this point fuel drawn through nor vale 28. Valve 29 is controlled by the adjustment oi spring 30, as described. to open at the same reduced pressure in the secondary chamber at which liquid is drawn through nozzle 28, and, of course, valve 29 is opened wider at still higher speeds to supply additional air for the additional fuel drawn through nozzle- 28. t is to be noted that air is always passing through the secoiuilary chamber before nozzle 28 comes into operation.

Liquid accumulates in the depression (5" only when the float is depressed to permit a flow of fuel from o ifice 9 to the depression G for the purpose of priming; the enp'ine. At other times when the engine is ope: any tliuel flowing through the orifice 9 will be taken up by the ingoing' air stream and no ccumulation oil -luel in the depression 6 will occur. i

I claim as my invention:

1. In a carburetor, the combination of a mixing chamber having an air inlet passage and a fuel inlet, an auxiliary air inlet passage communicating therewith and having an air inlet opening at its outer end, an inwardly opening valve for closing the opening between said ai'ixiliary air inlet and the mixing chamber, a second valve normally closing the air inlet at the outer end of said passage, a spring normally closing said. first valve, a second spring controlled by the first spring and operating to l'lOSQ tie second valve, and an auxiliary fuel nozzle opening into the passage between said valves.

2. In a carburetor, the combinati on with a casing having communicating primary and secondary mixing chambers, the latter comrnrisiup; an air inlet of fixed area and a normally closed inlet, oi? means for supplying fuel to each of the two chambers. a valve controlling the normally closed inlet, and a valve opening and closing; automatically separating; the two chambers and which is operated by differences in pressure in the latter first to admit a given volume of air into the primary chamber from the inlet of fixed area and second, to cooperate with the first mentioned valve and said inlet to con trol the degree of the reduction of pressure produced in the secondary chamber relative to that produced. in the primary chamber.

3. In a device of the character described the combination of a casing-having a primary mixing chamber, air supply means and fuel supply means therefor, a secondary mixing chamber connected by a passage with the primary chamber, a valve for said passage operated automatically by differences in pressure between said primary and secondary chambers, a fuel supply means for the secondary chamber, air supply means for said secondary chamber provided with means for adjusting the same to different constant sizes to produce the pressure in the secondary chamber required to operate said fuel supply means thereof at a predetermined pressure in said primary chamber, and automatic air supply means for supplying additional air to the secondary chamber during; the operation of said fuel supply means thereof. I

l. In a device oi": the character described,

the combination of a. casing having a priniary mixing); chamber. air supply means and fuel supply means thereforba secondary mixing" chamber connected by a passage'i with the primary chamber, a fuel supply means for the secondary chamber, an automatic pressure operated valve controlling said connecting passage, air inlet means at fordingz a continuous supply of air to said secondary chamber, and manually operable means for-adjusting said inlet means to difl e/rent constant sizes unaffected by pressure to produce. in the secondary chamber the pressure required to operate said. fuel. supply means thereolat a predetermined pressure in said primary chamber.

WINFIELD P. PEMBROKE.

Witnesses:

G. VVILLAPD RIOH,

Russell. E. GRIFFITH. 

